         (repeatedly (fn [] (typical-surface-treating-pressure arg)))))
 
 (defn rand-injection-rate-unit []
-  (rand-nth [:bbl-per-min :bpm :l-per-s :cu-ft-per-s]))
+  (rand-nth [:bbl-per-min :bpm :m3-per-min :m3/min]))
 
 (defn typical-injection-rate
   ([]
-   (let [units (rand-injection-rate-unit)]
-     (typical-injection-rate units)))
-  ([units]
-   (cond (or (= units :bbl-per-min)
-             (= units :bpm))
+   (let [unit (rand-injection-rate-unit)]
+     [unit (typical-injection-rate unit)]))
+  ([unit]
+   (cond (or (= unit :bbl-per-min)
+             (= unit :bpm))
          (value-from-typical-range 75 100)
-         (= units :l-per-s)
-         (value-from-typical-range 198.75 265)
-         (= units :cu-ft-per-s)
-         (value-from-typical-range 7.05 9.4))))
+         (or (= unit :m3-per-min)
+             (= unit :m3/min))
+         (value-from-typical-range 11.92 15.9))))
 
 (defn injection-rate-seq [arg]
   (cond (int? arg)

        (keyword? arg)
        (repeatedly (fn [] (typical-injection-rate arg)))))

(defn typical-proppant-concentration
  ([]
   [:ppga (typical-proppant-concentration :ppga)])
  ([units]
   (cond (= units :ppga)
         (value-from-typical-range 0.2 10))))

(defn proppant-concentration-seq [arg]
  (cond (int? arg)
        (let [unit :ppga]
          [unit (take arg (proppant-concentration-seq unit))])
        (keyword? arg)
        (repeatedly (fn [] (typical-proppant-concentration arg)))))

                   [:kPa :MPa] #(/ % 1000)
                   [:C :F] #(+ (* % 1.8) 32)
                   [:ft :m] #(/ (* % 30.48) 100)}]

    (converter [from to])))

(defn typical-monitor-pressure [units]
